The production rates depends on the type of material, thikness and pipe diameter. Better to distinguish between small and large bore, the rates are totaly differents. Use inch for estimating the progress of welding and tonnage for estimating the errection progress.

Thanks, but this is our daily bread so to speak, we get paid to think, and thinking is about asking questions about what you dont know rather than what you know. To a lot of people thinking means dreaming about something nice.
Regards

Where is the guy working?
What is the specs?
What is the material?
What is the schedule of pipe?
Is heat treatment required?
Is HAZOPS a question?
What is the NDE requiorements?
Kow many Questions are there?
Think it through/

I beg to differ on this issue.
Refinery/Petrochem Projects are demanding & much more complicated than building works.
Piping works are not so simple as Civil/Structural or building works.
Study & decipher Piping GADs & ISOs, Piping materials are huge & diverse unlike Civil/structural materials.
Fabrication & erection have different rates,
Site fabrication, Shop fabrication, Pre-fabricated spools are have different welding rates which also depends on the Material of Construction (MOC) & ofcourse craftsmanship.
SAme is with Piping erection, since this involves work at site, its productivity is low compared to fabrication.
Factors affecting erection rate are MOC, Height of erection, Erection of Pipe Rack or around Equipments & others.
Piping work does not end here.
In fact, it will serve all if the various productivity rates are displayed (country-wise, job-wise etc), but will planners share such vital information?????

Below Major Pointers for doing an estimate. (The Easy way is to take it from a book)

First we have a look at the Delivery. = HOW WILL THE PIPE GET THERE. Once we know this we can estimate an delivery estimate.

Then we have a look at Fitup = What type of pipe is it is. Is it Seamed / Seamless / Finwall / Thik Wall / Rolled / Spiral/ preped / macine prep. All This can effect the the time for the Fitup

Then we have a look at the Weld it self. I would suggest only work with Arc Time then Add Reel / Rod Changes / Setup etc. (The Reason with different method of Welding Example Stick / Mig etc) Will have differnet time Then you add Effeciency / Job Difuiculty Factors / QA / Material Type / etc.

There are variables that will affect the estimates (metalurgy, diameter, thickness, #welds, etc.). We have a system that can assist you with preparing estimates, plans and schedules for piping erection, but it is not free (see link below).